Dormer, hip-to-gable and mansard loft conversion drawings for Mendip Hills homes — prepared to Somerset Council's design guidance, delivered in days and revised free until your decision lands, with a free approval-odds score first.
Somerset Council granted 94% of the householder planning decisions it made in its latest published year — 7 points above the 87% England-wide householder average. Mendip Hills contains Chewton Mendip, Kilmersdon, Litton conservation areas (Chewton Mendip designated 1988), so materials, fenestration and roof form are assessed against the appraisal, which is where a policy-literate drawing pack earns its keep. Its dominant Victorian (1837–1901) and postwar (1945–1970) housing stock sets the design brief on most streets.
Class A and Class B set the thresholds — a rear dormer to 40m³ on a terrace or 50m³ on a semi or detached, and a single-storey rear extension to 3m on a terrace or 4m on a detached house — beyond which Somerset Council needs a full application. In conservation areas such as Chewton Mendip, Kilmersdon and Litton those rights are removed, so we confirm your exact address before a line is drawn. A validated householder application in Mendip Hills is determined against an 8-week statutory target.
Chewton Mendip (conservation area designated in 1988), Kilmersdon (conservation area designated in 1985), Litton (conservation area designated in 1987), Mendip Hospital (conservation area designated in 1991), Oakhill (conservation area designated in 1991), Ashwick (civil parish within Mendip Hills), Binegar (civil parish within Mendip Hills), Chewton Mendip (civil parish within Mendip Hills), Chilcompton (civil parish within Mendip Hills), Emborough (civil parish within Mendip Hills) and Holcombe (civil parish within Mendip Hills) — these are the Mendip Hills pockets our drawings cover most. Heritage designations here include Chewton Mendip, Kilmersdon, Litton, Mendip Hospital and Oakhill. Somerset Council weighs each proposal against the adopted Somerset local plan and Somerset Council's design guidance for householder work, where the 4,590 homes here are 29% pre-1900, 11% 1993-1999, 9% 1965-1972, which is what sets the realistic roof and rear-projection options. On roofs the borough is steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building and trussed-rafter roofs typical of 1990s building, over Victorian and earlier houses (29% of 4,590 homes), 1990s estate houses (11%) and late-1960s and early-1970s houses (9%).
Heritage designation is the single biggest variable in Mendip Hills, and it is address-specific: Chewton Mendip (conservation area designated in 1988), Kilmersdon (conservation area designated in 1985), Litton (conservation area designated in 1987), Mendip Hospital (conservation area designated in 1991) and Oakhill (conservation area designated in 1991). Inside those boundaries permitted development is curtailed and Somerset Council assesses materials, window detail and roof form against the area's own appraisal, so a scheme that would be waved through two streets away can need a full application here.
Beyond the designated areas, Mendip Hills takes in Ashwick, Binegar, Chewton Mendip, Chilcompton, Emborough and Holcombe. No Article 4 direction is recorded for Somerset Council, but Mendip Hills's 5 conservation areas still limit permitted development on those streets.
On stock, Mendip Hills is Victorian and earlier houses (29% of 4,590 homes), 1990s estate houses (11%) and late-1960s and early-1970s houses (9%) — which is why steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building and trussed-rafter roofs typical of 1990s building govern what a loft or rear projection can realistically be. Somerset Council decided 1,422 householder applications in the latest published year and granted 94%, with 74% issued inside the eight-week target. We work from the council's own published record.
The full build-period split for Mendip Hills runs pre-1900 29% (1,310 homes), 1900-1918 3% (130 homes), 1919-1929 3% (140 homes), 1930-1939 6% (270 homes), 1945-1954 6% (270 homes), 1955-1964 4% (190 homes), 1965-1972 9% (430 homes), 1973-1982 7% (330 homes), 1983-1992 3% (160 homes), 1993-1999 11% (500 homes) and 2000-2008 6% (260 homes). That distribution is why pre-1900 detailing dominates the drawings here, and it is measured from council-tax records rather than assumed from the street name.
Somerset Council also decides for Blackdown & Neroche, Blackmoor Vale, Brent, Bridgwater South, Bridgwater West, Brympton, Burnham on Sea North and Cannington, so a decision in Mendip Hills sits inside a wider pattern of decisions we track across the same authority — useful when an officer cites a precedent from the next area over.
Published figures for Mendip Hills and Somerset Council. These are the numbers that decide what is realistic on your street, so we work from them rather than from national averages.
| Measure | Mendip Hills |
|---|---|
| Dwellings recorded | 4,590 |
| Built pre-1900 | 1,310 (29%) |
| Built 1900-1918 | 130 (3%) |
| Built 1919-1929 | 140 (3%) |
| Built 1930-1939 | 270 (6%) |
| Built 1945-1954 | 270 (6%) |
| Built 1955-1964 | 190 (4%) |
| Built 1965-1972 | 430 (9%) |
| Built 1973-1982 | 330 (7%) |
| Built 1983-1992 | 160 (3%) |
| Built 1993-1999 | 500 (11%) |
| Built 2000-2008 | 260 (6%) |
| Built before 1919 | 31% |
| Built 1919–1939 | 9% |
| Built 1945–2008 | 47% |
| Conservation areas in Mendip Hills | 5 (Chewton Mendip, Kilmersdon…) |
| Conservation areas district-wide | 178 |
| Article 4 directions recorded | 0 |
| Householder applications decided | 1,422 |
| Householder applications granted | 94% |
| Decided within 8 weeks | 74% |
Dwelling stock from VOA council-tax data at 31 March 2025; conservation-area and Article 4 counts from planning.data.gov.uk (MHCLG); decision figures are Somerset Council's own, from MHCLG live table PS2 for the year to 31 March 2026.
Mendip Hills's roofs set the brief. The borough is built largely from Victorian and earlier houses (29% of 4,590 homes), 1990s estate houses (11%) and late-1960s and early-1970s houses (9%), and its lofts sit under steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building and trussed-rafter roofs typical of 1990s building — the geometry that decides whether a rear dormer, a hip-to-gable or a mansard gives you the headroom you want. Somerset Council assesses loft proposals against the adopted Somerset local plan and Somerset Council's design guidance for householder work, and its case officers read each roof against the pair next door and the wider street before they read the plans.
That makes drawing quality decisive. We measure ridge and eaves heights, roof pitch and the existing stair, calculate the added volume against the permitted-development limits exactly, and show the workings on the drawings so Somerset Council can verify them. Mendip Hills contains Chewton Mendip, Kilmersdon, Litton conservation areas (Chewton Mendip designated 1988), so materials, fenestration and roof form are assessed against the appraisal, so we resolve it on the page rather than leave it for the case officer to raise.
Mendip Hills also carries protected streets — Chewton Mendip, Kilmersdon, Litton, Mendip Hospital and Oakhill among them. No Article 4 direction is recorded for Somerset Council, but Mendip Hills's 5 conservation areas still limit permitted development on those streets. We check your address against those designations before a line is drawn.
Many Mendip Hills loft conversions proceed without planning permission — a rear dormer within the permitted-development volume limits (40 cubic metres on a terrace, 50 on a semi or detached house) is usually lawful. You will normally need a full application to Somerset Council if any of these apply:
We draw the roof line, the ridge height and the neighbour's daylight on the page — the relationships Somerset Council's officers check first — and submit a validation-complete pack, whether that is a lawful development certificate or a full householder application.
Below is Somerset Council's real householder decision record, pulled from official planning statistics and updated as new data lands. Somerset Council granted 94% of its householder applications in the year to 31 March 2026, and Chewton Mendip shapes what is approved here. Professionally prepared loft drawings anticipate those pressure points before submission, which is why complete, policy-literate packs are decided faster and refused less often than DIY applications.
Source: MHCLG planning application statistics (householder decisions, England, 1 April 2025 - 31 March 2026). Compare every borough on our London approval-rate league table.
Tell us about your project and get a fixed, no-obligation quote back within one working day. If you don't need planning permission at all, we'll tell you that too — for free.
Across Chewton Mendip, Kilmersdon and Litton, the recurring loft is the rear dormer — a box across the back roof slope that turns a cramped attic into a full-height double bedroom and en-suite. On steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building, that is usually the most efficient use of the roof; where the stock is trussed-rafter roofs typical of 1990s building, a hip-to-gable followed by a rear dormer unlocks far more space, though it needs a full application.
The 4,590 homes here are 29% pre-1900, 11% 1993-1999, 9% 1965-1972, which is what sets the realistic roof and rear-projection options. We draw the dormer inside the volume allowance, keep the flat-roof build-up below the ridge, and set the face back from the eaves as the rules require — so the pack answers Somerset Council's questions before they are asked. Where permitted-development rights are exhausted or removed, we prepare a householder application composed to the borough's roof-alteration guidance instead.
We draw loft conversions on every street in the borough. A few of the neighbourhoods where Mendip Hills roofs come up most often:
Loft conversion drawings for Chewton Mendip's conservation area designated in 1988 — measured, volume-checked and drawn to Somerset Council's guidance.
Loft conversion drawings for Kilmersdon's conservation area designated in 1985 — measured, volume-checked and drawn to Somerset Council's guidance.
Loft conversion drawings for Litton's conservation area designated in 1987 — measured, volume-checked and drawn to Somerset Council's guidance.
Loft conversion drawings for Mendip Hospital's conservation area designated in 1991 — measured, volume-checked and drawn to Somerset Council's guidance.
Loft conversion drawings for Oakhill's conservation area designated in 1991 — measured, volume-checked and drawn to Somerset Council's guidance.
Loft conversion drawings for Ashwick's civil parish within Mendip Hills — measured, volume-checked and drawn to Somerset Council's guidance.
The right loft in Mendip Hills depends on your roof. This is how the main types compare on planning route and the space they add.
| Loft type | Permitted development? | Space & headroom | What Somerset Council checks |
|---|---|---|---|
| Rear dormer | Usually yes, within volume limits | Full-height double room at the back | Volume, set-back from eaves, ridge height |
| Hip-to-gable | No — full application | Extends the whole side of the roof | Roof bulk and the symmetry of the pair |
| Mansard | No — full application | Maximum floor area across the roof | Street character, especially in conservation areas |
| Rooflights only | Usually yes (Class C) | Light and headroom, no extra footprint | Whether rooflights sit within the existing slope |
Route depends on your street — conservation areas such as Chewton Mendip and Kilmersdon and Article 4 directions can remove permitted-development rights.
A fixed process built around how Somerset Council validates and decides householder loft applications — most drawings are submission-ready within seven days of survey.
Tell us your Mendip Hills postcode and roof type. We confirm your conservation and Article 4 status, how much permitted-development volume you have left, and score your odds against live Somerset Council decisions.
We measure ridge and eaves heights, roof pitch, joist levels and the existing stair — the numbers the volume calculation and head heights depend on.
Chartered designers develop the dormer, hip-to-gable or mansard to your brief, drawn inside the Class B limits or to Somerset Council's roof-alteration guidance.
We submit the certificate or application, manage validation and case-officer queries, and revise the drawings free until Somerset Council issues its decision.
Often not. A rear dormer within 40 cubic metres on a terrace, or 50 on a semi-detached or detached house, set back from the eaves and no higher than the ridge, is usually permitted development. In Mendip Hills the main exceptions are hip-to-gable conversions, dormers visible from the highway, and homes in conservation areas such as Chewton Mendip and Kilmersdon or on streets with an Article 4 direction. Somerset Council is the decision-maker.
Generally no. In conservation areas including Chewton Mendip and Kilmersdon, Class B permitted-development rights for lofts are removed, so a rear dormer that would be lawful elsewhere needs a full application to Somerset Council. No Article 4 direction is recorded for Somerset Council, but Mendip Hills's 5 conservation areas still limit permitted development on those streets. We check your exact address before drawing.
On steeply pitched slate roofs, valley gutters and party parapets typical of pre-1900 building, common across Mendip Hills, a rear dormer is usually the most efficient conversion and often permitted development. Where the roof is trussed-rafter roofs typical of 1990s building, a hip-to-gable followed by a rear dormer gains far more usable space but needs planning permission. Our survey confirms which your roof supports before we draw. Somerset Council is the decision-maker.
A householder planning application in Mendip Hills runs to a statutory eight-week target, and a lawful development certificate to eight weeks as well, though validation can add time if the pack is incomplete. We submit validation-complete drawings and manage case-officer queries to keep the decision on track. Somerset Council is the decision-maker.
If your dormer is permitted development, a lawful development certificate from Somerset Council is council-stamped proof of that — worth having, because every buyer's solicitor will ask for it when you sell. We prepare and submit the certificate application with the same drawing pack. This applies to your Mendip Hills address specifically.
Every roof is different, so we quote each Mendip Hills project individually — a fixed, no-obligation price back within one working day. The quote covers the full drawing pack with free revisions until Somerset Council approves, and we tell you upfront whether your loft qualifies as permitted development. Call 020 7864 7245 to start.
Answer five quick questions and get a free planning score for your exact address — instantly. Then, if you want the full picture, unlock the detailed analysis: your council's live approval rates, local precedents, constraints on your street and a step-by-step route to permission.
Same fixed quotes, same fast drawings — wherever your project is.